Authorities are investigating the death of a 65-year-old man who was found unresponsive Thursday afternoon near downtown Arlington Heights.

The man was found about 3:30 p.m. near Arlington Heights Road and Northwest Highway, according to police in the northwest suburb. Foul play isn’t suspected in the death, which appeared to be of natural causes.

An autopsy Friday did not immediately rule on the cause and manner of his death pending further investigation.